According to this article "Non stop growth for online travel", It's completly true because today people have less time to go directly in travel agency.
They prefere more to take time go in the website and make their choice.
It is easy to do, you have time to make your choice and it is more clear and the best things is you can measure what you can going to pay without any suprises.
And the things his nowadays you can book all for your future destinations, I mean Travel, Hotel, Restaurants, leisures...!
This business is really important for hotellers because that allows them to sell more online through their owns websites.
It is a new revolution and that is a good thing.